“…Cluster analysis has proven to be useful in demonstrating the variability of a cohort, providing more information than group analyses per sé (Glenn, Cunningham, Poole, Reeves, & Weidling, 2008). The clustering methods have been successfully employed in infant temperament research (Janson & Mathiesen, 2008), in parenting studies during infancy (Meteyer & Perry-Jenkins, 2009) and in analyses of caregivers' behavior during free interaction (Hofer, Hohenberger, Hauf, & Aschersleben, 2008). This approach was also employed to categorize both infant and maternal gaze direction and vocalization within a play condition (Kawai et al, 2010), infant looking features when presented with different kinds of object-in-motion video stimuli (Kutsuki, Kuroki, Egami, Ogura, & Itakura, 2009), and infants at risk for autism during a video interaction task based on the FFSF paradigm, that is by a TV-video interaction (Merin, Young, Ozonoff, & Rogers, 2007).…”